Wireless antenna for wireless charging and NFC communication and wireless terminal to which same is applied

ABSTRACT

A wireless antenna includes a wireless communication antenna including a first wireless communication coil and a second wireless communication coil; and a wireless charging antenna comprising a wireless charging coil. Further, the wireless charging coil is disposed inside the first wireless communication coil, and the second wireless communication coil is disposed inside the wireless charging coil.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is the National Phase of PCT International ApplicationNo. PCT/KR2016/007303 filed on Jul. 6, 2016, which claims the benefitunder 35 U.S.C. § 119(a) to Korean Patent Application No.10-2015-0096051 filed on Jul. 6, 2015, all of which are hereby expresslyincorporated by reference into the present application.

BACKGROUND OF THE INVENTION Field

This disclosure relates to a wireless antenna, and more particularly, toa wireless antenna capable of simultaneously supporting wirelesscharging and near field communication (NFC) and a wireless terminal towhich the same is applied.

Discussion of the Background Art

Due to the development of mobile communication and informationprocessing technologies, smart phones provide various wireless Internetservices such as content services as well as video telephony. Such smartphones use near-field communication (NFC) technology to provide theaforementioned services.

NFC technology is non-contact near-field wireless communication using afrequency band of 13.56 MHz and is a communication technology thattransmits data bidirectionally between terminals within a distance of 10cm or less.

Moreover, design technologies for wireless antennas are evolving suchthat, in recent smart phones, a loop antenna having a wireless chargingfunction and a loop antenna having the above-mentioned NFC function areprovided together in order to enhance user convenience.

Wireless charging is non-contact charging in which charging is achievedsimply by placing a smartphone on or near a charger. As a wirelesscharging method, a magnetic-induction method, a magnetic-resonancemethod, and an electromagnetic-wave method may be mentioned, and amongthese, the magnetic-induction method has recently attracted attention.

However, in the related art, since a very small smartphone has had to beprovided with a loop antenna that supports magnetic induction wirelesscharging and a loop antenna that supports NFC, charging efficiency maybe reduced or NFC recognition efficiency may be deteriorated due tointerference between the two loop antennas.

SUMMARY

To overcome the problem described above, one object of this disclosureis to provide a wireless antenna designed such that a loop antenna thatsupports an NFC function is added inside a loop antenna that supportswireless charging, and a wireless terminal to which the same is applied.

In addition, another object of this disclosure is to provide a wirelessantenna designed by optimizing the distance between a loop antenna forwireless charging and an additional loop antenna having an NFC function,and a wireless terminal to which the same is applied.

According to one embodiment of this disclosure, there is provided awireless antenna including a near field communication (NFC) antennaincluding a first coil member and a second coil member each including atleast one first loop pattern, and a charging antenna including aninduction coil member including at least one second loop pattern formedbetween the first coil member and the second coil member and a coilperiphery member configured to form an inner periphery of the inductioncoil member.

The NFC antenna may further include a coil connection member connectedto one side of an inner surface of the first coil member and to one sideof an outer surface of the second coil member.

The second coil member may include inner turns, a number of which isdetermined within a range satisfying a resistance (R) value or a qualityfactor (Q) value, which is defined in standards of a Wireless PowerConsortium (WPC) and a Power Matters Alliance (PMA).

The second coil member may include one inner turn.

The second coil member and the coil periphery member may have a distancetherebetween, which is determined within a range satisfying the R valueor the Q value.

The R value may range from 4Ω, to 6Ω, and the Q value may range from 23to 27.

The distance between the second coil member and the coil peripherymember may range from 40 μm to 70 μm.

The NFC antenna may further include a first longitudinal end of thefirst coil member configured to extend from one side of the innersurface of the first coil member.

The second coil member may be formed so that a second longitudinal endterminal formed on a longitudinal end of the first loop pattern thereofis in electrical contact with the longitudinal end terminal.

Each of the first loop pattern and the second loop pattern may be formedas a spiral loop pattern.

According to another embodiment of this disclosure, there is provided awireless terminal including a wireless antenna configured tosimultaneously support wireless charging and near field communication(NFC), a flexible printed circuit board (FPCB) on which the wirelessantenna is mounted, a battery configured to store therein electric powergenerated in the wireless antenna, and an NFC chip configured to supplyelectric power to the NFC antenna so as to transmit and receivecommunication data to and from the NFC antenna.

Each of the first loop pattern and the second loop pattern may be formedas a spiral loop pattern.

The wireless antenna may be bent so as to be divided and formed on twosurfaces of the flexible printed circuit board.

As described above, in the embodiments, a first coil member and a secondcoil member, which support near field communication (NFC), are formedinside and outside of an induction coil member, which supports wirelesscharging, and are connected to each other, whereby wireless charging maybe achieved and increased NFC recognition efficiency may be achieved.

In addition, when the distance between the second coil member and a coilperiphery member is determined or the number of inner turns of thesecond coil member is optimally determined within a range satisfying aresistance (R) value or a quality factor (Q) value defined in standardsof the WPC and the PMA, interference therebetween may be suppressed.

Accordingly, when interference is suppressed, this may result in anincrease in wireless charging efficiency and NFC recognition efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are cross-sectional views respectively illustrating anexample of the antenna structure of a wireless antenna according to anembodiment.

FIG. 3 is a cross-sectional view illustrating the connection structureof the wireless antenna illustrated in FIG. 1.

FIG. 4 is a graph illustrating the R value compared with the inner turninterval depending on the number of inner turns of FIGS. 1 and 2.

FIG. 5 is a graph illustrating the comparison result between the Q valueand the inner turn interval of FIGS. 1 and 2.

FIG. 6 is a schematic view illustrating one example of a wirelessterminal to which the wireless antenna of FIG. 1 is applied.

FIG. 7 is a schematic view illustrating another example of a wirelessterminal to which the wireless antenna of FIG. 1 is applied.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Terms described below in this specification are merely used to describespecific embodiments, and the embodiments should not be limited by theseterms. For example, the terms “first coil member” and “second coilmember” are used to distinguish one element from another element.

Moreover, the term “and/or” used in this specification should beunderstood as including any arbitrary and all possible combinations ofone or more of the associated listed items.

Hereinafter, embodiments disclosed herein will be described in detailwith reference to the accompanying drawings, and the same referencenumbers will be used throughout the drawings to refer to the same orlike parts, and a repeated description thereof will be omitted.

Embodiment of Wireless Antenna

FIGS. 1 and 2 are cross-sectional views respectively illustrating anexample of the antenna structure of a wireless antenna according to anembodiment.

As illustrated, the wireless antenna 100 according to an embodimentincludes an NFC antenna 110 for near field communication (NFC) and acharging antenna 120 for wireless charging in connection with a coil ofthe NFC antenna 110.

The NFC antenna 110 includes a first coil member 111, which includes atleast one first loop pattern 111 for NFC, and a second coil member 112,which is formed inside the first coil member 111 and includes at leastone first loop pattern 112 in the same manner as the first coil member111.

The first loop pattern has a structure in which several spiral patternsare wound in close contact with each other. For example, the first looppattern of the first coil member 111 may include substantiallyrectangular spiral patterns, and the first loop pattern of the secondcoil member 112 may include substantially circular spiral patterns.

In conclusion, the first loop pattern of the first coil member 111 andthe first loop pattern of the second coil member 112 may have the samespiral pattern structure, but may differ from each other in terms of theshape thereof. However, the disclosure is not limited thereto, andvarious modifications, for example, one in which both loop patterns havethe same shape, are possible.

Here, the first loop pattern of the second coil member 112 may belimited as to the number of spiral patterns, unlike the first looppattern of the first coil member 111.

This is because it is necessary to satisfy a resistance (R) value and/ora quality factor (Q) value, which are defined in standards of theWireless Power Consortium (WPC) and/or the Power Matters Alliance (PMA).

In general, the R value is defined within a range from 4Ω to 6Ω, and theQ value is defined within a range from 23.00 to 27.00, as recommended inthe standards of the WPC and/or the PMA.

Since efficiency may be deteriorated in terms of wireless chargingand/or NFC recognition outside the ranges described above, the standardsof the WPC and/or the PMA define the ranges as described above.

Thus, the first loop pattern of the second coil member 112 may bedetermined so that the number of spiral patterns is within both theranges of the R value and/or the Q value described above.

For example, when the first loop pattern of the second coil member 112includes one inner turn (“turn” means the number of times the coil iswound), this may be the optimum number in terms of wireless chargingefficiency and/or NFC recognition efficiency.

In other words, when the first loop pattern of the second coil member112 includes one inner turn, it may satisfy the R value and/or the Qvalue, thereby enhancing wireless charging efficiency and/or NFCrecognition efficiency.

Meanwhile, an example of one inner turn is illustrated in FIG. 1, and anexample of two inner turns is illustrated in FIG. 2. As noted above, oneinner turn in FIG. 1 is superior to two inner turns in FIG. 2 in termsof the effect thereof.

On the other hand, in an embodiment, the charging antenna 120 is formedbetween the first coil member 111 and the second coil member 112 of theNFC antenna 110, in order to satisfy both antenna standards, which arerecommended in the standards of the WPC and the PMA.

To this end, the charging antenna 120 may include an induction coilmember 121, which includes at least one second loop pattern, and a coilperiphery member 122, which forms the inner periphery of the inductioncoil member 121.

The second loop pattern has a structure in which several spiral patternsare wound in close contact with each other. For example, the second looppattern of the induction coil member 121 may include substantiallycircular spiral patterns.

The coil periphery member 122 may have a size sufficient to cover thebottom of the induction coil member 121 so as to be larger than theinner circle and the outer circle when the induction coil member 121 hasa circular shape.

For example, the coil periphery member 122 may form the outer periphery,which protrudes outwards from the circular induction coil member 121,and may also form the inner periphery, which protrudes inwards from thecircular induction coil member 121.

Next, the NFC antenna 110 according to an embodiment may further includea coil connection member 113, which connects one side of the innersurface of the first coil member 111 and one side of the outer surfaceof the second coil member 112 to each other. As shown in FIG. 1, a widthof a winding of the second coil member 112 is less than a width of awinding of the first coil member 111, and each of the windings of thefirst coil member 111 has a width greater than the width of the windingof the second wireless communication coil (e.g., the various dimensionsare readily seen at the center left of FIG. 1, where the connectionmember 113 connects between the first coil member 111 and the secondcoil member 112).

Through the connection using the coil connection member 113 as describedabove, the first coil member 111 and the second coil member 112 may beelectrically connected to each other so as to further activate theinterchange of magnetic fields between the first coil member 111, thesecond coil member 112, and the induction coil member 121, which mayincrease NFC recognition efficiency and charging efficiency.

Moreover, in order to further increase NFC recognition efficiency andcharging efficiency, the distance L between the second coil member 112and the inner periphery of the coil periphery member 122 (hereinafteralso referred to as an inner turn interval) may be determined within therange satisfying the resistance (R) value and/or the quality factor (Q)value, which are defined in the standards of the WPC and/or the PMA.

For example, when the R value, recommended in the standards of the WPCand/or the PMA, ranges from 4Ω to 6Ω, or when the Q value, recommendedin the standards of the WPC and/or the PMA, ranges from 23.00 to 27.00,the distance L may range from 40 μm to 70 μm to satisfy the R value orthe Q value.

The suitability therefor will be sufficiently described later withreference to FIGS. 4 and 5.

Embodiment of Connection Structure

FIG. 3 is a cross-sectional view illustrating the connection structureof the wireless antenna illustrated in FIG. 1. Reference numeralsillustrated in FIG. 3 designate the same structure including theabove-described reference numerals of FIG. 1.

Referring to FIG. 3, the wireless antenna 100 according to an embodimentmay include the connection structure of the NFC antenna 110 and theconnection structure of the charging antenna 120.

With regard to the connection structure of the NFC antenna 110, thefirst coil member 111 may further include a longitudinal end terminal114, which extends from one side of the inner surface of the first coilmember 111 and forms a first longitudinal end of the first coil member,and the second coil member 112 may further include a second longitudinalend terminal 115, which is wound by the number of inner turns and isformed on the longitudinal end of the second coil member.

The longitudinal end terminal 114 may be spaced apart from the secondcoil member 112, but may extend from the inner side of the first coilmember 111, rather than being connected to one side of the inner surfaceof the first coil member 111 and to one side of the outer surface of thesecond coil member 112.

In this case, the second longitudinal end terminal 115 may be inelectrical contact with the longitudinal end terminal 114. This contactstructure may contribute to an increase in NFC recognition efficiencyand charging efficiency.

In addition, the connection structure of the NFC antenna 110 may furtherinclude an inner connection terminal 116, which is formed on the otherinner longitudinal end of the last spiral pattern of the first looppattern formed on the inner surface of the first coil member 111.

The connection terminal 116 may be in electrical contact with aconnection terminal 117, which is formed on the outer longitudinal endof the first coil member 111.

In an embodiment, the connection structure of the charging antenna 120may further include a connection terminal 123, which is in electricalcontact with a battery, in order to transmit electric power, which isgenerated via the magnetic-induction-type magnetic field between the NFCantenna 110 and the charging antenna 120, to the battery.

The connection terminal 123 of the charging antenna 120 may be formed inthe direction in which it crosses the second loop pattern having aspiral shape.

However, the disclosure is not limited thereto, and the charging antennamay be positioned in various ways depending on the inner structure of anobject on which the wireless antenna 100 is mounted (e.g. a mobileterminal, a wearable device, or the like). Moreover, needless to say,the connection structure of the NFC antenna 110 may have various othercontact structures depending on the inner structure or shape of theobject.

Meanwhile, the wireless antenna 100 described above may be formed(printed) on a flexible printed circuit board 101. In this case, eachconnection structure of the wireless antenna 100 may be electricallyconnected to a connector 102, which is formed on the flexible printedcircuit board 101. The connector 102 may be electrically connected to,for example, an NFC chip, which is provided inside the object.

Comparative Example 1

FIG. 4 is a graph illustrating the R value compared with the inner turninterval depending on the number of inner turns of FIGS. 1 and 2.

Referring to FIG. 4, when the number of inner turns is zero, the R valueranges from 3Ω to 4Ω to correspond to the optimally determined range ofthe inner turn interval from 40 μm to 70 μm. When the number of innerturns is one, which is optimal, the R value ranges from 4Ω to 6Ω tocorrespond to the determined range of the inner turn interval from 40 μmto 70 μm.

On the other hand, it can be seen that, when the number of inner turnsis two, the R value ranges from 6Ω to 8Ω to correspond to the optimallydetermined range of the inner turn interval from 40 μm to 70 μm.

Here, since the R value must range from 6Ω to 8Ω as recommended in thestandards of the WPC and/or the PMA, NFC recognition efficiency andcharging efficiency could be increased under the specification in whichthe inner turn interval ranges from 40 μm to 70 μm and one inner turn isprovided to satisfy the above-described range of the R value.

It can be appreciated that this increase in efficiency results from thestructure of the NFC antenna 110 described with reference to FIGS. 1 and2 as well as the above-described specification in which the inner turninterval ranges from 40 μm to 70 μm and one inner turn is provided.

The other two specifications with regard to the inner turn interval andthe number of inner turns do not satisfy the R value recommended in thestandards of the WPC and/or the PMA, and thus inevitably causedeterioration in NFC recognition efficiency and charging efficiency.

Comparative Example 2

FIG. 5 is a graph illustrating the comparison result between the Q valueand the inner turn interval of FIGS. 1 and 2.

Referring to FIG. 5, when the number of inner turns is two, the Q valueranges from 17 to 22 to correspond to the optimally determined range ofthe inner turn interval from 40 μm to 70 μm. When the number of innerturns is one, which is optimal, the Q value ranges from 23 to 27 tocorrespond to the determined range of the inner turn interval from 40 μmto 70 μm.

On the other hand, it can be seen that, when the number of inner turnsis zero, the Q value ranges from 30 to 33 to correspond to the optimallydetermined range of the inner turn interval from 40 μm to 70 μm.

Here, since the Q value must range from 23 to 27 as recommended in thestandards of the WPC and/or the PMA, NFC recognition efficiency andcharging efficiency could be increased under the specification in whichthe inner turn interval ranges from 40 μm to 70 μm and one inner turn isprovided, which satisfies this range.

The other two specifications with regard to the inner turn interval andthe number of inner turns do not satisfy the Q value recommended in thestandards of the WPC and/or the PMA, and thus inevitably causedeterioration in NFC recognition efficiency and charging efficiency.

Embodiment of Wireless Terminal

FIG. 6 is a schematic view illustrating one example of a wirelessterminal to which the wireless antenna of FIG. 1 is applied.

Referring to FIG. 6, the wireless terminal 1000 according to anembodiment includes the wireless antenna 100, a flexible printed circuitboard (FPCB) 200, a battery 300, and an NFC chip 400. The wirelessantenna 100 has sufficiently been described above with reference toFIGS. 1 to 5, and thus, a description thereof will be omitted below, butthe above description may be equally applied to the present embodiment.

First, the flexible printed circuit board 200 is disposed in a givendirection inside the wireless terminal 1000 so that loop patterns of thewireless antenna 100 are formed thereon. The flexible printed circuitboard 200 may be mounted inside a battery pack.

The battery 300 serves to store therein electric power transmitted fromthe wireless antenna 100. The battery 300 may be a detachable battery ora fixed battery.

Finally, the NFC chip 400 supplies electric power to the NFC antenna 110and transmits and receives communication data to and from the NFCantenna. The NFC chip 400 may include at least one of a tag or a reader.

For example, when an external device (not illustrated), which performsNFC with the wireless terminal 100, is a reader, the NFC chip 400 mayoperate as a tag. When the external device operates as a tag, the NFCchip 400 may operate as a reader. However, the NFC chip 400 may operateas both the tag and the reader.

Thus, the NFC chip 400 may read data recorded in the tag and/or thereader.

Meanwhile, the wireless terminal 1000 described in the presentembodiment may receive various Internet services via NFC, and may beapplied to a mobile terminal, which enables wireless charging duringmovement.

However, the disclosure is not limited thereto, and it can be said thatany other wireless device in which both wireless charging and NFC needto be implemented falls within the scope of the wireless terminaldescribed in the present embodiment. For example, the wireless terminalmay be a large-scale wireless device such as an automobile wirelessdevice as well as a portable wireless device such as an MP3 player or awearable device.

Another Embodiment of Wireless Terminal

FIG. 7 is a schematic view illustrating another example of a wirelessterminal to which the wireless antenna of FIG. 1 is applied.

Referring to FIG. 7, the wireless terminal 1000 according to anembodiment includes the wireless antenna 100, which simultaneouslysupports wireless charging and NFC, a flexible printed circuit board(FPCB) 500 on which the wireless antenna 100 is mounted, the battery300, which stores therein electric power generated in the wirelessantenna 100, and the NFC chip 400, which supplies electric power to theNFC antenna 110 provided in the wireless antenna 100 and transmits andreceives communication data to and from the NFC antenna 110.

Here, the flexible circuit board 500 may be the same as the structure ofthe flexible printed circuit board 200 described in FIG. 6 in terms ofthe function thereof, but may have a difference therebetween in that,when the wireless terminal 1000 is provided with a bent region 1001, theflexible circuit board is divided and provided on, for example, an uppersurface 1002 and a rear surface 1003 of the wireless terminal 1000.

A portion of the flexible printed circuit board 500 and the wirelessantenna 100 may be disposed on the upper surface 1002 of the wirelessterminal 1000, and the remaining portion of the flexible printed circuitboard 500 and the wireless antenna 100 may be disposed on the rearsurface 1003 of the wireless terminal 1000.

However, the bending and placement position of the wireless antenna 100described above are merely given by way of example, and it may beimportant for the wireless antenna to be disposed in the bent state.

The reason for this placement is to allow the wireless antenna to beeasily applied to a compact wireless terminal such as the small wirelessterminal 1000 or the flexible wireless terminal 1000.

Thereby, in the present embodiment, the wireless antenna 100 is bent andplaced over several surfaces, thus having increased applicability tovarious kinds of wireless terminals.

Although embodiments have been described above with reference to theaccompanying drawings, it will be apparent to those skilled in the artthat the embodiments may be realized in other particular forms within arange that does not deviate from the spirit and essential features ofthe embodiments. Thus, the above detailed description should not beconstrued as being limited in all terms, but should be considered to beexemplary.

Embodiments described above may be applied to a terminal that requireswireless charging, for example, a cellular phone, a smart phone, a smartpad, a notebook, a table PC, a laptop computer, a digital broadcastingterminal, a personal digital assistant (PDA), a portable multimediaplayer (PMP), and the like. However, those skilled in the art willeasily appreciate that the disclosure is not limited thereto, and mayalso be applied to a terminal installed in a vehicle, and the like.

The invention claimed is:
 1. A wireless antenna comprising: a wirelesscommunication antenna comprising a first wireless communication coil anda second wireless communication coil; and a wireless charging antennacomprising a wireless charging coil, wherein the wireless charging coilis disposed inside the first wireless communication coil, and the secondwireless communication coil is disposed inside the wireless chargingcoil, and wherein a width of a winding of the second wirelesscommunication coil is less than a width of a winding of the firstcommunication coil.
 2. The wireless antenna according to claim 1,wherein the first wireless communication coil has a substantiallyrectangular shape, and the second wireless communication coil has asubstantially circular shape.
 3. The wireless antenna according to claim1, wherein the first wireless communication coil and the second wirelesscommunication coil have a different numbers of windings.
 4. The wirelessantenna according to claim 3, wherein the number of windings of thesecond wireless communication coil is one.
 5. The wireless antennaaccording to claim 3, wherein the number of windings of the firstwireless communication coil is greater than the number of windings ofthe second wireless communication coil.
 6. The wireless antennaaccording to claim 3, wherein a number of windings of the wirelesscharging coil is greater than the number of windings of the firstwireless communication coil.
 7. The wireless antenna according to claim1, wherein the wireless communication antenna comprises a coilconnection member configured to interconnect the first wirelesscommunication coil and the second wireless communication coil.
 8. Thewireless antenna according to claim 7, wherein the coil connectionmember overlaps the wireless charging coil.
 9. The wireless antennaaccording to claim 1, wherein the first wireless communication coil andthe second wireless communication coil are connected to each other inseries, and wherein the first wireless communication coil and the secondwireless communication coil are wound so as to have a same currentrotation direction.
 10. The wireless antenna according to claim 1,wherein the wireless communication antenna and the wireless chargingantenna are formed on a flexible printed circuit board.
 11. The wirelessantenna according to claim 10, wherein the flexible printed circuitboard comprises a connector connected to the wireless communicationantenna and to the wireless charging antenna.
 12. The wireless antennaaccording to claim 3, wherein a number of windings of the wirelesscharging coil is greater than the number of windings of the secondwireless communication coil.
 13. The wireless antenna according to claim1, wherein a diameter of an innermost coil of the second wirelesscommunication coil is at least one and a half times as large as adistance between an innermost turn of the wireless charging coil and anoutermost turn of the wireless charging coil.
 14. The wireless antennaaccording to claim 1, further comprising: a coil periphery member onwhich the wireless charging coil is disposed.
 15. The wireless antennaaccording to claim 14, wherein a portion of the first wirelesscommunication coil is disposed outside the coil periphery member. 16.The wireless antenna according to claim 14, wherein the coil peripherymember has a substantially larger area than an area of the wirelesscharging coil.
 17. The wireless antenna according to claim 14, whereinthe coil periphery member outwardly extends beyond an outer boundary ofthe wireless charging coil, and the coil periphery member inwardlyextends beyond an inner boundary of the wireless charging coil.
 18. Thewireless antenna according to claim 14, wherein the coil peripherymember includes a notched portion disposed adjacent to an inner cornerof the first wireless communication coil, a portion of the notchedportion being located outside of the wireless charging coil and withoutoverlapping the wireless charging coil.
 19. The wireless antennaaccording to claim 14, wherein the coil connection member overlaps thecoil periphery member.
 20. The wireless antenna according to claim 14,wherein the second wireless communication coil is disposed inside thecoil periphery member.
 21. The wireless antenna according to claim 14,wherein the coil periphery member extends beyond an outermost edge ofthe wireless charging coil without overlapping with the portion of thefirst wireless communication coil.
 22. The wireless antenna according toclaim 14, wherein an inner corner of the first wireless communicationcoil is spaced apart from the coil periphery member.
 23. The wirelessantenna according to claim 18, wherein the portion of the notchedportion is disposed between an outermost turn of the first wirelesscommunication coil and an outermost turn of the wireless charging coil.24. The wireless antenna according to claim 18, wherein the notchedportion only extends partially into the coil periphery member withoutextending all the way through the coil periphery member.